Bug report: can not parse DynamoDBAttributeValue on aws lambda

Hi, I wrote a lambda function to process DynamoDB Stream data, when I try to parser value about "NewImage" and "OldImage" field in DynamoDB Stream events according to

https://github.com/aws/aws-lambda-go/blob/master/events/README_DynamoDB.md

In this document, it says we could use `value.Integer()` to read a integer value, this works well in local test.
But we I deploy lambda into aws, the error occur:

accessor called for incompatible type, requested type 5 but actual type was 0: IncompatibleDynamoDBTypeError

I try to print the DynamoDBAttributeValue, it looks normal: { "N":"123456"}

Is there any method to fix this issue?